YAML Input

Java Output

What is YAML to Java Converter?

This tool converts YAML data structures into Java POJO (Plain Old Java Object) classes. The converter generates a Java class with private fields inferred from the YAML keys, along with getter and setter methods following Java naming conventions.

YAML strings produce String fields, whole numbers produce int (or long once they pass 2,147,483,647, so an accountId of 3000000001 doesn't overflow), decimals produce double, booleans produce boolean, and unquoted dates such as 2024-01-15 produce String. Lists become typed List<...> fields when every item has the same type.

Nested mappings become public static nested classes inside Root, with the field typed as that class, so the whole output is one Root.java that compiles as-is. Keys that aren't valid Java names are fixed up: first-name becomes firstName, 2fa becomes _2fa, and reserved words like class get a trailing underscore.

How to Convert YAML to Java

Follow these steps to generate a Java POJO class from your YAML data.

Paste or Upload Your YAML

Paste your YAML into the left panel, or click Upload to load a .yaml file. Click Sample for an example. Example YAML:

user:
  id: 1001
  name: Ava Chen
  email: [email protected]
  active: true
  roles:
    - admin
    - editor

Click Convert

There's no button to press: the right panel updates as you type, showing one Root.java with private fields, getters and setters, and a static nested class for each nested mapping.

Copy or Download the Java Code

Click Copy to copy the Java code to clipboard, or Download to save as a .java file. Rename the class as needed and add it to your project.

When You'd Use This Tool

API Model Generation

Generate Java model classes from YAML API schemas for use with Jackson or Gson in REST API implementations.

Spring Boot Config

Convert Spring Boot application.yml configuration to Java @ConfigurationProperties classes for type-safe config binding.

Data Binding

Generate Java POJOs from YAML data files for use with SnakeYAML or Jackson YAML data binding.

Microservices

Convert YAML service contract definitions to Java model classes for microservice communication contracts.

Frequently Asked Questions

What Java types are inferred from YAML values?

String → String, whole number → int (long above the int range, BigInteger past the long range), decimal → double, boolean → boolean, date → String, null → Object. A list whose items share one type becomes List<String>, List<Integer> and so on; a mixed or empty list becomes List<Object>.

Are nested YAML objects converted to separate classes?

Yes. Each nested mapping becomes a public static class inside Root, and the parent field uses that type (private Address address;). A list of mappings becomes a list of a generated class, named from the key (orders gives List<Order>). The class is built from the first item, so check it against the rest of your data.

Is the generated code production-ready?

The generated code provides a starting point. You may need to add annotations like @JsonProperty, adjust types, or add validation for production use.

Is my YAML data sent to a server?

No. All conversion happens in your browser. Your YAML never leaves your device.

Can I use this with Spring Boot's @ConfigurationProperties?

Mostly. The getters and setters follow the JavaBean convention that Spring's externalized configuration binding uses, and its relaxed binding maps first-name in your YAML onto firstName. Annotate the class you bind (for example Customer) with @ConfigurationProperties(prefix = "customer") and register it; the generated Root wrapper usually isn't needed for that.

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